CNN  — 

A US Capitol Police officer was indicted on obstruction charges in connection to the January 6 insurrection at the US Capitol.

According to the indictment, Michael A. Riley told a contact online to remove posts showing the person was in the Capitol building that day.

Riley’s arrest is notable among the more than 600 Capitol riot cases in that he becomes the first police officer on duty on Capitol Hill on January 6 charged with allegedly attempting to help a rioter.

The 50-year-old was arrested Friday and appeared in court on a video feed from a holding cell. He has not yet entered any plea and is not being detained pending trial, but will be barred from possessing any guns as he awaits trial. He is scheduled to be arraigned on Tuesday.

Prosecutors allege that on the day after the insurrection, Riley sent a private message on Facebook to a person who had posted selfies and videos about being in the Capitol, and whom Riley had been in fishing-related Facebook groups with.

“im a capitol police officer who agrees with your political stance,” Riley allegedly wrote to the person, according to the indictment. “Take down the part about being in the building they are currently investigating and everyone who was in the building is going to charged. Just looking out!”

“Im glad you got out of there unscathed We had over 50 officers hurt, some pretty bad,” Riley also messaged to the person that day.

In mid-January, Riley told the person to “Get off of social media.”

“Theyre arresting dozens of people aday. Everyone that was in the building, engaged in violent acts, or destruction of property…and theyre all being charged federally with felonies,” Riley allegedly wrote.

They also spoke on the phone, prompting the person Riley communicated with to tell others about being in touch with “capitol police” and to anticipate trespassing charges.

Riley has been placed on administrative leave, USCP Chief Tom Manger said.

“Obstruction of Justice is a very serious allegation. The Department was notified about this investigation several weeks ago. Upon his arrest, the officer was placed on administrative leave pending the completion of the case. The USCP’s Office of Professional Responsibility will then open an administrative investigation,” Manger said in a statement.

Riley had worked with the Capitol Police for 25 years, the indictment said. He was in the K-9 unit on January 6, though he was not on duty inside the Capitol building during the attack, prosecutors say, and responded to reports of an explosive device on Capitol Hill that day.

Riley then deleted his own Facebook direct messages on January 20, his indictment says. Riley indicated in a final message on January 21 he was angry with the person after seeing video of the person smoking marijuana in the Capitol and “acting like a moron,” the indictment says.

“Michael Riley has served honorably as a United States Capitol Police officer for over 25 years. We look forward to fighting the charges brought against him in court,” Riley’s attorney David Benowitz said in a statement on Friday.

Man wanted to start ‘a revolution’ on January 6

The man whom Riley allegedly warned is Jacob Hiles, according to a person familiar with the case and descriptions in court records.

Hiles was not named in the indictment, which referred to a person who was arrested on January 19 and was asked by the FBI about communicating with Riley, according to the allegations.

Hiles, of Virginia, said on social media that he traveled to Washington, DC, while thinking about starting “a revolution,” according to investigators.

In selfies from January 6 found by the FBI on social media, Hiles wore a gaiter mask and ski goggles and a sweatshirt that said “F*ck Antifa.” He had also posted on his Facebook page, “Feelin cute … might start a revolution later,” tagging himself on Capitol Hill, according to documents supporting his arrest.

Hiles was arrested on January 19 and released from custody with an order to stay away from Washington. In September, he pleaded guilty to one federal charge, of parading or demonstrating inside the Capitol, according to court records.

Hiles attended the pro-Trump “Stop the Steal” rally with his cousin from Ohio, and the pair marched to the Capitol after Trump spoke, according to court records. He has agreed to pay $500 for damage to the Capitol and could face a maximum of six months in prison when he is sentenced in December.

“Mr. Hiles has done everything he can to be cooperative throughout this entire investigation,” defense attorneys Charles Haskell and Alex Bell told CNN. “Mr. Hiles is receiving no benefit in exchange for his cooperation and he intends to do everything he can to put this incident behind him.”

This story has been updated with additional details.

CNN’s Whitney Wild contributed to this report.